Dental articulator



Oct. 29, 1935. J. l. LAWSON DENTAL ARTICULATQR Filed Nov. 20, 1954 BY NATTORNEYS Patented Oct. 29, 1935 UNITED STATES PATENT OFFIQE 1 Claim.

of which proper occlusion of dentures will be obtained. Other objectswill appear in the course of the following description of a deviceembodying the invention which resides in certain novel featuresparticularly set forth in the appended claim.

In the drawing:

Figure 1 is a perspective view of the articulator.

Figure 2 is a vertical section.

Figure 3 is a detail section on the line 33 of Figure 2.

Figure 4 is a perspective view showing a modification.

In carrying out the present invention, there is provided a lower plate Iwhich is of skeleton construction so that when a plaster cast is appliedthereto the plate will be partly embedded and the cast firmly held. Uponthe edge of the plate is an extension 2 from which rise spaced parallellugs 3 connected at their outer vertical edges by a web 4 which, asshown clearly in Figure 2, terminates short of the upper ends of thelugs, the lugs and the web being integral with the plate. Pivoted at itslower end to and between the lugs 3 is a stem or standard 5 which ispreferably rectangular in cross section and may be of any desiredlength. The lower extremity of the standard is below the pivot and thepivot is so located that when the standard is raised, as shown in fulllines in Figure 2, its lower end will bear against the web 4 and thestandard cannot swing forward and down under the weight of a denture orcast. When the standard is swung back and down, as shown by dotted linesin Figure 2, it will rest upon and be supported by the web, and theparts should be so proportioned that the standard will fit closelybetween the lugs and be thereby prevented from swaying laterally butwill turn easily when it is to be raised or lowered.

An upper plate 6 is provided having substantially the same contour asthe lower plate and also of skeleton construction. The extension 1 ofthe upper plate, however, is wider than the extension 2 of the lowerplate and has guide ribs 8 along its edges on its upper side betweenwhich fits an arm 9. Said arm 9 is formed with a longitudinal slotthrough which a thumb screw or bolt II is inserted to engage a threadedopening in the extension I and thereby secure the upper plate in a setposition, a washer or a shoulder 12 being provided under the head of thescrew to span the slot and clamp the arm and plate together as the screwis turned home. The arm 5 9 extends from a collar l3 which fits snuglybut slidably around the standard and is held in a set position on thestandard by a thumb screw l4 mounted in the collar to be turned homeagainst the standard. The non-circular cross section of 10 the standardand of the bore of the collar aid the thumb screw in preventing lateralswaying of the arm after it has been adjusted vertically on thestandard. A set screw 24 mounted in the side of the collar I3 preventslost-motion in the 16 event of Wear.

In the variation shown in Figure 4, the lower plate has a fiat-sidedpost I5 thereon and the standard l6 has its lower end formed into a forkII which fits over the upper end of the post and 20 is pivoted thereto,the ends of the fork having arcuate edge portions I8 concentric with thepivot and stop shoulders I9 to abut stop lugs or studs 20 on the postand thereby prevent the standard rocking downwardly and forwardly. 25

The use of the device will be readily understood. The casts, indicatedat 2| and 22, are mounted on the upper and lower plates and the teeth 23are fitted on the casts, the arm 9 being adjusted vertically on thestandard according to 80 the length of the teeth. By adjusting the upperplate upon the arm 9 the upper denture can be properly centered over thelower denture and the ribs 8 effectually prevent lateral slipping of theplate. By rocking the standard on its pivot 35 until it rests on the web4 or the studs 20, as the case may be, the dentures will be firmlysupported while adjustments of the teeth are made and the occlusion andbite of the teeth may be closely observed by slowly rocking the standardto open and close the dentures.

Having described my invention, what I claim is:

A dental articulator comprising a lower plate,

a pair of upstanding lugs on said plate, a web connecting the outeredges of the lugs and terminating short of the upper ends of the lugs, astandard pivoted adjacent its lower end to and between the lugs andarranged to bear against the front face of the web or rest across theupper end of the web, and an upper plate carried by the standard.

JAMES IRA LAWSON.

